Arm64Emitter: Remove duplicate IsPowerOf2 function

We can just use the generified version in MathUtil.

Source/Core/Common/Arm64Emitter.cpp

@@ -12,6 +12,7 @@
 #include "Common/Arm64Emitter.h"
 #include "Common/Assert.h"
 #include "Common/CommonTypes.h"
+#include "Common/MathUtil.h"
 
 namespace Arm64Gen
 {
@@ -37,11 +38,6 @@ static uint64_t LargestPowerOf2Divisor(uint64_t value)
   return value & -(int64_t)value;
 }
 
-static bool IsPowerOfTwo(uint64_t x)
-{
-  return (x != 0) && ((x & (x - 1)) == 0);
-}
-
 #define V8_UINT64_C(x) ((uint64_t)(x))
 
 bool IsImmArithmetic(uint64_t input, u32* val, bool* shift)
@@ -187,7 +183,7 @@ bool IsImmLogical(uint64_t value, unsigned int width, unsigned int* n, unsigned
   }
 
   // If the repeat period d is not a power of two, it can't be encoded.
-  if (!IsPowerOfTwo(d))
+  if (!MathUtil::IsPow2<u64>(d))
     return false;
 
   // If the bit stretch (b - a) does not fit within the mask derived from the